2. There are almost certainly superior alternatives to Paulson or even (especially?) to Paulson-as-modified (see, for example, this).

3. There's not enough time to write a new plan, get a consensus behind it, etc.

So: 4. We need to pass Paulson-as-modified ASAP.

McCain will throw his weight behind it and help get it through. But he will also makes clear that, as president--while of course standing behind all obligations incurred and transactions committed to under the Paulson regime--he's going to take a fresh look. He's going to convene the best people, he'll take a look at all the best ideas that have been put forward (ranging from Hillary Clinton's to Newt Gingrich's, from direct aid to housing to rights offerings by banks to changing accounting rules, etc.), and he will then plan on modifying/improving/adding to the Paulson plan going forward. This is delicate: McCain needs to reassure markets about the current commitments as well as promise further and better reforms. But this is the right position substantively and, I think, politically. It combines the best of McCain's impulses, and the twin requirements of presidential leadership: taking responsibility for what has to be done now, and committing to energetic and bold reform in the near future.